WO2011095832A1

WO2011095832A1 - High performance multilayer modular (cellular) structural system

Info

Publication number: WO2011095832A1
Application number: PCT/IB2010/000227
Authority: WO
Inventors: Francesco Cavalieri
Original assignee: Di Benedetto, Marco
Priority date: 2010-02-05
Filing date: 2010-02-05
Publication date: 2011-08-11

Abstract

The object of this invention is a High Performance Multilayer Modular (Cellular) Structural System. It is a system with multidisciplinary applications through which it is possible to create high performance multilayer structures by means of union of cellular modular multilayer elementary units, according to various compositions. This invention is not a finished product but a methodological principle for constructing multilayer systems, elementary or composites, whose the geometry is fundamental feature and necessary property for their realization. That composite system provides alternative solutions to create panels, walls, insulating structures, carrying structures, protecting structures, dividing structures, membranes, corroborate elements for other systems, micro and macro containment structures, self-supporting structures in general, fuselages, tanks, vehicle bodies, coatings, coverings, filling elements, basic elements able to be molded, chassis,etc... The system can be realized with any materials, which also allows the realization of Structural Systems at low cost, with excellent mechanical and insulation properties, with a good relation between mass and volume (lightness), bringing benefits in terms of working production cost, transport, installations,etc...in many fields/sectors (general construction, works of engineering,etc...).

Description

High Performance Multilayer Modular (Cellular) Structural System

DESCRIPTION

The object of this invention is a High Performance Multilayer Modular (Cellular) Structural System.

It is a system with multidisciplinary applications through which it is possible to create high performance multilayer structures by means of union of cellular modular multilayer elementary units, according to various compositions.

This invention is not a finished product but a methodological principle for constructing multilayer systems, elementary or composites, whose the geometry is fundamental feature and necessary property for their realization, reproducible through rigorous and precise overlap of layers.

Result of a geometric-structural study on multilayer cells, that composite system provides alternative solutions to create panels, walls, insulating structures, carrying structures, protecting structures, dividing structures, membranes, corroborate elements for other structures, micro and macro containing structures, self-supporting structures and in general, fuselages, tanks, vehicle bodies, coatings, coverings, filling elements, basic elements able to be molded, chassis, etc...

The system can be realized with any materials: simple or composite, plastic or elastic, organic or inorganic, natural or industrial, mineral, vegetable, synthetic, etc...

Using a single material will result in mono-material structures.

Employing more than one material will result a multimaterial structures.

The above-mentioned system does not preview a differentiation in its composition: indeed fine materials (pure/new materials examples: steels, woods, cellulose, fibers in general, resins, composites, etc.), can be used as well as poor materials and materials derived from recycling (waste/used materials examples: industrial wastes, waste derived from wood carving, vegetable fibers, papers, composite materials, synthetic materials, etc.).

The above-mentioned system allows the creation of structures that have features such as elevated lightness, high mechanical resistance(to compression, bending, traction,etc...), high thermal and acoustic insulation, as well as anti-seismic properties.

Clearly, different performances will be found according to the employed materials.

Another important feature is the particular attitude of the system to adapt itself to the used materials.

For this reason that system is multidisciplinary applicable, from architecture to engineering (aeronautical, naval, mechanical, civil, hydraulic, etc.) up to find employment in other fields such as manufacture (objects in general, sport equipments, health equipment, etc.).

With that method of structural composition are conciliated performances, qualities and advantages of high performance structures(examples: concrete structures, steel structures, etc... ) with the qualities of light and alveolar structures.

Moreover the particular structure makes it easy to improve the performances of the single layers or of the whole Structure(Structure System) by chemical, thermal, mechanical, etc... treatments.

The above-mentioned system has a multitude of constructive variables(geometric, chemical, etc.) which make possible to generate an infinite amount of structural systems: everyone will have peculiar composition(structural and chemical) and different behaviors.

This peculiarity can be seen from an economic-productive point of view it becomes an important feature of the system as it allows to realize micro and macro structures with good performances even employing materials normally not used in certain fields.

(example: the use of mineral, vegetable or animal fibers for the construction of carrying structures or insulators.)

In terms of safety should be highlighted that the particular structure allows to compartmentalize and monitorize it through structural verification: this is possible employing specific devices- both for occasional and permanent verifications.

(example n. 1- verification of eventual infiltrations of a hull following a collision,

example n. 2- verification of the state of fact of a structure subordinate to solicitations due to events that could have damaged or put the system in different conditions than before the event) This feature represents a new peculiarity regarding the traditional construction systems, such as systems in wood, concrete, brick or similar for construction, as well as for those in steel or fiberglass for boats or for the realization of containment, insulation, protection, etc... structures.

The same feature also allows to modify generated systems adapting them according to functions, needs or requirements(functional and structural): it allows, for example, to insert corroborative materials with specific function, elements or systems/plants between the layers.

Analyzing the state(status) of the art it is possible to say that there are no known multilayer-systems of this kind in any field.

The structural system introduced here is created and developed as a behavior study of multilayer- cells and the modular composite structures obtained from their union.

Simplified the analysis of the construction system it is possible to say :

The structural system is generated by the sum of the modular cells (that for it may present a multitude of geometrical, compositional, etc...variables);

Each modular structural cell is obtained by the union and the overlap of layers(that for it may present a multitude of geometrical, compositional, etc... variables);

Fundamental elements are the geometrical relations between the layers.

Each Layer presents peculiarity correlated to the used materials, its geometries, etc...(that for it may present a multitude of geometrical, chemical, physical, etc... variables).

Dividing symmetrically a cell in a perpendicular way to the superposition of layers, it is possible to identify the basic units that compose it. Their modularity is one of their main properties. Their union through geometric rules create the cells. Their shape determines the shape of the cells.

The compositive system begins from the processing data of individual materials used until the shape of the finished structure. It analyzes and monitors each step of the process(FIG 8).

Furthermore it is possible to apply additional treatments(chemical, mechanical, thermal, etc..) or corroborative elements to the system or part of it to obtain different performances with the use of anisotropic materials, another important parameter it's the orientation of the fibers: this allows to obtain different performances depending on how those are applicated and solicited.

Every elementary Cell is composed by the overlap of 5 layers (4+1): 4 layers that constitute the basic-nuclear cell (2 linear + 2 not linear ones overlapping alternately) and a last linear layer to add on the curvilinear side with the task to close the system(TABLEl - here the Nonlinear profile present a sinusoidal profile)

The nonlinear layers may present various geometries, with regular or irregular, curvilinear or broken profiles.

For that the system functions properly it is necessary to respect a regular structural sequence generated from the alternation of linear and nonlinear layers

Example: T + O + T + O + T

possibly even with the overlap of layers similar

Example: ... + Τ + 0 + Τ + Τ + 0 + Τ + ...

Example: ... + 0 + T + O + O + T + 0 +...

Where T = Layer with Linear profile

O = Layer with Nonlinear profile

The structures could also use a sequence composition in which the system is opened and/or closed with Nonlinear layers.

Example O + T + O + T + O

From a compositional/geometricalnumerical point of view it is possible summarize the overlapping System with the following formula:

n

C = ∑ (Oi+Ti) + Ti*

i=l where n = It represents the number of Structural Layer generated by the union of a cellular linear layer and a corrugated one in each Cell. Li = (Oi+Ti)

Ti = Linear layer(cell layer)

Oi = Corrugated/Shaped Layer(cell layer)

Ti'= It represents the last linear layer that closes the Cell .

Adding the LayerT to the generic Open Cell(c) we obtain the Closed Cell(C). The linear layers(T) are fundamental elements characterizing of the system.

Their task is to balance and stabilize elements: in fact they work like distributors, homogenizing solicitations to which the system is submitted and ensuring maximal cohesion and participation of every single layer, increasing and maximizing the contact surfaces of the nonlinear layers.

Their presence represents a necessary and indispensable condition to obtain a structure with uniformed solicitations on every single layer.

This would not occur if these are lacking: the structure indeed would be solicited differently and it would present different structural behaviors and lower performances.

The nonlinear layers(O) instead have the function to give rigidity and structural resistance/strength to the structure.

The layers are correlated by the angle of rotation(P) generated around the axis Z by the corrugated layers(TABLE 2).

Considering the perpendicular axis Z to the basic plan XY, the rotation angle β generated around it self can create different systems/structures with different geometries, different constructive relationships between the layers, and consequently with different characteristics and performances. Structurally the better relationship will be obtained using determined geometries, in which that angle of rotation is between 0° and 180°.

The best performances will be obtained approaching β to 90°(TABLE n.2) and with the angle γ next to 45°, where γ is the angle created by the corrugated layers on the development plan XZ(TABLE 4.3).

Moreover, thanks to the particular morphology of the combination of the layers, the gaps created inside the structure generate insulating properties.

It is possible to analytically monitor and manage these properties from the phase of design.

The angles β and γ may be considered during the design process for a better use of the materials (isotropic materials, anisotropic materials,etc.) and applicable treatments(mechanical treatment,chemical treatment,etc.)

For example, the use of flimsy or anisotropic materials is possible for the creation of performing structures by optimizing their peculiarities and by creating a balance of forces in the system.

Considering the use of a generic "Open Cells "composed by 4 layers(Tl+01+T2+02 - where the number beside the letter indicates the layer considered in the multilayer cell ), the structural System which proceeds can be considerate as a result of the following summation:

Sn = cl+c2+...cn + T' (T3*)

where the first linear layer (Tl) of each Cell is the closing one of the next Cell (T3)

(T' = Tl = T3*) and "n" represents the number of the considered cells.

In this system it is possible to add a final layer T3*necessary to close the system, as mentioned in the general formula.

This assumption is valid when the system is not a circle-system where T3cl = Tlcn, where in this case "n" is the last cell on the structural system.

In this case we have the number of elementary layers nL = 4cn+l .

In a circle/system the number of layers is nL = 4cn where n is the number of cells.

Another possibility is the use of "Closed Cells" composed, at least, by 5 layers(3 linear layer + 2 corrugated layer) and indicated by "C"

The elementary system obtained is:

Sn = (C1+C2+ ... Cn) where nL = 5Cn. These assumptions are valid only to explain the logic of the composition: to apply the composition system it is necessary to use a complete and complex system of composition that give the possibility to control the geometry of the system and not just the number of the Cells .

Knowing the characteristics of individual cells, this method can be useful for the calculation of other system characteristics(weight, quantity of materials used, volume, etc.).

In every Cell each layer can be:

- Simple: composed of a single layer of material

Composite: composed of several layers of material joined together The combination of several layers with different features (for example the orientations of the fibers

- crossed or uncrossed) can guarantee to the layers and to the system better performances.

The overlap of the layer may be obtained by

where "a" represents the angle of rotation generated by the rotation of the non-linear layers around an axis parallel to Z which passes through the center of the cell and perpendicular to XY(TABLE 2).

The angle β generated by the overlap of the layers and consequently by the angle a and α' is comprised between 0° and 180°( 0°< β °< 180°).

With a larger number of different layers and angles of rotation angle β is treated differently in the design of systems, because they are more angles of relationship between the layers and not just one. With β = 0° or 180° it is obtained the overlap of parallel layers.

Considering the overlap of two regular profiles with β = 0° or 180° and 3 equivalent points/vertexes of those(points/vcrtexes A and A' in the layer 02, and point/vertex B in the layer 01) the infinite variables of the relation between layers are given by the positioning of point/vertex B in the interval AA'. (TABLE 4 and TABLE 4.1)

With the overlap of B with A' the system corresponding to the starting system: in fact System B / A and B / A' are equivalent.

The best performances are obtained with β = 90° and γ = 45°, where γ is the angle generated by the encounter of the inclined plane of the layers corrugated with the plan/surface where the Structural System works(plane XZ, TABLE 4.3).

The system also provides the possibility to create structures with corrugated layers with different geometrical features.

This means that the discourse on the variables on the positioning of the layers in the system can also be made to different profiles, evaluating the different geometries and the possible variables

(TABLE 4.1 and TABLE 4.2).

The basic Structural System is constituted by a minimum of 4 Cells(TABLE 5).

The systems themselves can be added horizontally and/or vertically to obtain largest Structural

System.

Furthermore the system also can be rotate in every direction for giving different performances being an anisotropic structure.

In addition, the overlap and the union of modular Systems can be considered another variable of the final System: it can comply orders of composition and individual/different structural systems, everyone with a multitude of variables defined as independent from the others. Example of Structural System: Sab which assumes a"Doublelayer" system in which each layer has its own characteristics.

Sa = where the forming cells may have a multitude of variables.

Sb = "

From the union of Structural Systems we obtain "modular complex systems".

They can be indicated by "nS" where "n" is the number of Structural Systems used

(example: 3 Sab - Triple Structure doublelayer equivalen to the union of three simple systems doublelayer. We obtain a more complex Structural System).

Analyzing the system S in terms of property/performance in relation to its modular structure, it is possible to say that the generic property of the system is

m

i=l

where Pc = represents the generic property of a single Cell,

m = represents the number of cells in the system.

The generic thermo-acoustic-mechanical property of the system (PS) is expressed by

y i=l j

z j=l k

k=l

Where Pci = is the generic "P" property that characterizes the basic elementary cell (C)

j of the system in its three main components(on its main directions x,y,z). k

m,n,p = are the number of cells in the three dimensions that compose the system.

Pc can be expressed by:

q

z

Where is a coefficient given by the interaction between layer and layer.

This value will be≠ 0 only along the axis perpendicular to the orientation of layers (axis of overlap),

q = is the number of layers of the basis cell.

A generic single Structural Layer(Li) of the structure and not of the Cell is composed by a linear layer of material(Ti) and a corrugated one(Oi). From a point of view of its properties it is possible to say that:

y y y y

Z Z Z X where δτο = represents a coefficient given by the interaction between the linear layers and the corrugated layers.

Oi = represents the generic corrugated layer.

Every layer is influenced not only by the material used (M) and the possible treatments applied as the Ti layer (generic layer linear), but also depends on its geometry (G)

Ox = / (G, MO)

y

X

y

z

The variables of the composition system are therefore:

1) the amplitude of the radius of curvatures of the nonlinear profiles;

2) the type of curving(elliptic or curvilinear or irregular);

3) the distance between the linear layers(highness);

4) the relationship created by the angles of rotation of the nonlinear layers;

5) The number of cells in each structural layer (L);

6) The number of layers used in the structural system;

7) the dimensions of the linear layers inside the cell on which insist/work the nonlinear layers (consequently the distance between the vertex of the nonlinear layers changes)

8) The rotation angle of each layer respect the axes of development(plan ZY, TABLE 6)

9) the rhythm of rotation between the layers(the relatioship between different angle β- TABLE 3): it can be constant, variable, progressive(es. Angle of increasing rotation), random, etc...

Also must be added the variables related to the material employed in the structure:

10) type of material

1 l)thickness of the material

12) possible structural improvements/treatments of the material(es. Adding of hardening elements/ components)

13) possible improvements/treatments to the structure(es. Molding of the layers )

Impossible internal or external complementary applications

15)the conscious use of fiber orientation

The employment of all these variables allows the management of the performances of the structure(insulating, acoustic, thermal,etc... performance), the quantity of gaps in the structure, the conductivity of the materials, the employment of eventual corroborative material,etc...

Claims

1) Multidisciplinary High Performance Multilayer Modular (Cellular) Structural System is able to create micro and macro structural systems with load bearing functions, insulating functions and containment functions.

2) Multidisciplinary High Performance Multilayer Modular (Cellular) Structural System is able to create micro and macro structural systems with load bearing functions, insulating functions,etc... and containment functions of preeminent use in architecture, in construction engineering ,naval engineering, mechanical engineering, structural engineering, hydraulic engineering.

3) Multidisciplinary High Performance Multilayer Modular (Cellular) Structural System is able to create micro and macro structural systems with load bearing functions, insulating functions and containment functions,etc... multifunctional and monitorable.